The word "shoe" is used herein in a broad sense, whenever the context so permits, to include all forms of outer foot wear. The word "lasting" is used herein in a broad sense to refer to the procedure of adhesively securing a shoe upper to an insole by means of a turned over margin of the upper which is stuck to the insole, for example by the use of a heat activatable adhesive.
It is conventional in the manufacture of shoes to carry out the lasting operations in three stages of which the first is either a seat lasting or a toe lasting operation and the final stage is a waist lasting operation.
We have found that advantages are obtained by departing from this sequence and in accordance with this invention in its broadest aspect the improved method of manufacturing a shoe includes the steps of arranging a closed upper so as to extend under tension around the back part of a back part mould, positioning an insole on the mould, performing a waist lasting operation in which both sides of the upper are lasted simultaneously, and then, while the upper is still arranged on the mould, performing a seat lasting operation.
Subsequently the shoe will be removed from the mould and positioned on a suitable last in another machine in which a fore part lasting operation is performed.
In this specification the expression "waist lasting" is to be understood as referring to a region of a shoe which not only includes the actual waist area but which may also extend from the seat area up to and including at least part of the point area.
The term "back part mould" means a mould which includes the back part and waist region of a normal last but omits the fore part of such last.
In another aspect this invention comprises a method of manufacturing a shoe in which a closed upper, which is supported under tension so as to extend round the back part of a last arranged bottom uppermost with an insole thereon, is waist lasted by means of two resilient bands arranged one on each side of the waist region of the last, each band being supported only at its upper and lower edges and so as to extend heightwise of the last, the method including the steps of advancing each band bodily towards the last so as to engage firstly the upper and bring it into contact with the widest part of the last and then progressively to conform the upper to the last both in the direction of the top line and the feather line of the shoe and lengthwise of the last, terminating the bodily movement of each band, and then while the lower edge of each band is held stationary moving the upper edge over and downwardly towards the last bottom so as to wrap the adjacent part of the band round the edge of the last and towards the last bottom whereby to turn the lasting margin of the upper over onto the insole.
This invention also includes apparatus for lasting the waist region of a shoe comprising a post supporting a last, two lasting assemblies mounted for movement widthwise of the last and adapted for engaging respective sides of the waist region of an upper when arranged on the last, each assembly including a single resilient band extending heightwise of the last and supported only at its upper and lower edges, means for moving the assembly towards the last so as to cause the band progressively to conform such upper to the last both in the direction of the top line and feather line of the shoe to be lasted and lengthwise of the last, means for preventing further movement of the assembly towards the last, and means for moving an edge of the band relative to the assembly both widthwise and heightwise of the last so that the part of the band adjacent the feather line is rolled over onto the last bottom whereby to turn over the lasting margin of such upper and press it onto an insole supported on the last.
Each assembly may include a plurality of presser feet arranged in a row extending lengthwise of the last and means for moving the presser feet relative to the assembly both widthwise and heightwise of the last to press the resilient band against the last bottom.
In carrying out the invention it has been found that while a greater or lesser number of presser feet may be used four presser feet will normally suffice for use in lasting a wide range of shoe sizes.
Preferably each presser foot is so mounted that it can take up the orientation of that part of the last bottom against which it is pressed.
Conveniently the presser feet are each pivotally mounted in pairs on a support member which in turn is pivotally mounted on one end of a pivoted lever the other end of which is connected with an actuator mounted on the assembly. Operation of the actuator causes the presser feet to be moved outwardly from the assembly and towards the last bottom so that the band is pressed thereagainst. To distribute the pressure exerted by the presser feet a plate of flexible material may be arranged beneath the presser feet and this plate may be spring mounted so that it is not normally in contact with these feet.
The assembly may be provided with a stop which conveniently engages the last through the band and acts to stop the further movement of the assembly towards the last.
In the use of the method of this invention the upper and an insole are heated prior to the lasting operation so as to activate adhesive on the insole or lasting margin of the upper and also to soften the upper and any stiffeners which may be incorporated therein. Alternatively adhesive could be applied to the insole or lasting margin of the upper when these are positioned on the last, prior to the lasting operation.
The improved apparatus of this invention is preferably constructed in such a way that after a waist lasting operation has been completed a post on which the last is mounted may be swung so as to carry the last into a conventional heel seat lasting and back part moulding machine, wherein seat lasting can be effected while the upper and insole are still warm.
In carrying out the invention it is convenient to use a back part mould instead of a normal last.